Many fungicidal azole compounds are known and have been developed.
N-(2-phenylethyl)succinamic acid (PESA) is known as an active ingredient of a plant growth regulator according to WO 99/45774, which describes amido acids, including PESA, that can be used with a fungicidal compound having root-enhancing activity (e.g., hydroxyisoxazole, metasulfocarb, metalaxyl). However, it does not mention enhancement by PESA of fungicidal activity of a fungicidal compound. Moreover, it also does not teach that the combination of PESA or a PESA salt with an azole fungicide can improve plant growth.